New research shows people on the autism spectrum have twice the risk of death of the general population.

The disturbing finding is the result of an Australian-first study at UNSW analysing linked datasets on death rates, risk factors and cause of death of 36,000 people on the autism spectrum in NSW.

It has led to a call for a holistic health and disability systems response to the issue to improve outcomes for this group.

“Our key finding is that people on the autism spectrum have elevated mortality across the lifespan – their overall comparative mortality rate is about twice that of the general population,” said Professor Julian Trollor from UNSW Medicine and Chair, Intellectual Disability Mental Health.

“This is of course of great concern. While we only looked at NSW data, we’d expect to find the same patterns nationally.

"It’s important to note the results do not point to elevated mortality for autistic people as a result of their being on the spectrum.

“Rather, the results indicate there needs to be a greater understanding of autism and co-occuring conditions within the health services sector, and that more equitable access to health services needs to be a priority for government and health service providers.”

Risk factors

The study also identified factors that influence mortality risk.

“Risk of death was associated with autistic people’s health needs – people with co-occuring conditions such as chronic physical illness, epilepsy and mental health conditions were at a higher risk of death. People who also had an intellectual disability had a higher risk, too.

“These insights are helpful because targeted strategies can be developed for those at higher risk.

“Unexpectedly, and different to the general population, we didn’t find demographic factors such as gender and socioeconomic status to be predictors of risk of death.”

Main causes of death

The team also found that the top causes of death were different for people on the autism spectrum.

“While the top causes of death in the general population were cancer and circulatory diseases, for people on the spectrum we found that injury and poisoning – which includes accidents, suicide and deaths related to self harm – was the single biggest cause of death, with nervous system and sense disorders (such as epilepsy) a close second,” said Professor Trollor.

“Combined with the information about mental health being a risk factor for death, the higher proportion of deaths from injury and poisoning may point to unmet mental health needs that this group is experiencing.

“Overall the high risk of death in people on the autism spectrum is a troubling indicator of the range of health inequalities experienced by this population.”

Andrew Davis, Autism CRC CEO, says the data will be invaluable in helping create strategies to improve health services and outcomes for people on the autism spectrum.

“We generally don’t have a lot of data on mortality rates, risk factors and cause of death in people on the autism spectrum – this piece of work is the first known use of large linked datasets to investigate mortality and cause of death for people on the autism spectrum in Australia,” Andrew Davis says.

“This is an issue, as understanding the drivers of excess mortality is important for those on the spectrum – and for those who support them, such as family members, health professionals and policymakers. This is particularly important where the deaths may be preventable,” he says.

The team says they now want to take the analysis of the data further.

“We'd like to be able to take this data and work back to understand the broader health requirements and unmet needs of this group. More resources would allow us to analyse health service use, health conditions and outcomes of people on the autism spectrum – not just focusing on death but also on overall health and pathways,” said Professor Trollor.

The results have been published in a leading academic journal in the field, Autism Research.